Go to Ron Ayers .com and pull up the microfiche on both bikes.  For the two heads to swap they would have to have similar gaskets (holes in the head matching those in the cylinder.)  They don't.

Not to mention that the DR650 has a 100mm bore to our 94mm.

But I wouldn't bet that Lancer couldn't make it work.

This is what I thought and even asked you guys what parts are from other motors and you told me NONE...........

I do know that the clutch is the same as a DR-500 but the rest is for the LS only.....

I wanted to hear it from you guys before I argued it with him...

And yes we can get the 100mm piston to work, I e-mailed a sleeve manufacture and they said they can make a sleeve and bore and install for around $250-$300 for a 100mm bore..

I'll stick with a stock sleeve bored and a fresh piston with a little more comp.....

Thanks guys.

Listen to the man's point about the clutch (he's been there, got two tee-shirts and hasn't gotten back yet) -- much work would have to be done to a LS to get it to go much past 50 hp and still connect that extra power to the ground.  

And if you did fix the clutch, what would be the next overstressed part in the power train to give up the ghost?  Shift dogs or shift forks?  Just guessing, but general durability issues under 2x extra power are quite common in severe hop up bikes.

What you need consider pursuing is the Lancer dual spark plug mod -- do that and you can get 65 hp easy with no durability issues.  My Lancer modded 650 Suzuki even gets improved gas mileage at the highest 65-70 hp rating, something that is appreciated more and more now-a-days.  Easy on the right hand and she's easy on your wallet.